The Analysis of Safety Impacts of “Near-Site” Traffic Signals

장일준 대한토목학회 2011 KSCE Journal of Civil Engineering Vol.15 No.7

Many approaches have been performed to reduce traffic accidents at signalized urban intersections in Korea. Among them installing red-light running cameras have been the most popular and simplest approach. Recently, on the other hand, engineering approaches have been tried and as a result, some provinces in Korea have started to install “near-site” traffic signals. Near-site signals are installed before crossing the intersection, aiming to reduce traffic violations and accidents at intersections. This new approach,however, has been performed without any in depth studies. Thus, this research attempts to verify the impact of near-site signals on traffic safety based on collected field data of drivers’ behaviors. Accident rates at signalized intersections with near-site traffic signals have been collected to study the direct effects of near-site signals. This study also collects violation rates of stop lines and traffic signals, and approach speed to examine the rate of reduction of possible risks at intersections. A simple comparison method has been applied. By comparing violation rates, approach speed, and accident rates, while excluding adjustment periods, this research finds that intersections with near-site signals can enhance traffic safety. Furthermore, this research suggests near-site signals should be installed at intersections that has the number of intersecting lanes are less than 6 lanes to maximize the impact on traffic safety.

경기도 교통사고 응급구조시스템 선진화방안 연구

장일준,허억,박지선,이재덕,김상태,김대호 경기연구원 2015 정책연구 Vol.- No.-

Analysis of Delay Reduction Effects on Modern Roundabouts according to the Entry Traffic Volume

장일준,안세영,한진석 대한토목학회 2013 KSCE Journal of Civil Engineering Vol.17 No.7

Modern roundabout installation is expanding nationwide in Korea recently. However, modern roundabouts are not installed extensively because of lack of effects analysis and the broad criteria for selection of the intersection. This study analyzes delay reduction effects based on the entry traffic volume in order to refine the selection criteria of the intersection. So roundabouts installed in 2010 were analyzed by traffic simulation (VISSIM). Consequently, the average entry traffic volume less than 110 (vphpl) or more than 400 (vphpl) is no effects of delay reduction. And by varying the traffic volume, the entry traffic volume 160~180 (vphpl)showed a greater reduction in delay.

보행상충을 고려한 보행사고 노출 추정 모형 개발

장일준,권남주,안세영 한국ITS학회 2023 한국ITS학회논문지 Vol.22 No.2

보행 교통사고를 예측하기 위해서는 보행 및 차량 통행량을 정확히 반영해야 한다. 그러나 보행량은 차량 통행량에 비해 측정에 어려움이 있다. 기존 연구는 직접 조사, 가구통행실태조 사 등을 통해 추정하였지만 이는 많은 비용과 시간이 소요되며 정확도가 떨어진다. 이에 본 연구는 적은 시간과 비용으로 실시간으로 데이터를 수집 및 분석할 수 있는 스마트폰을 활용 한 모바일 cctv를 대안으로 제시하였다. 본 연구는 사고로 발전할 수 있는 보행자-차량간 상충 을 보행사고 노출로 정의하였다. 대구 동성로 일대의 40개 구간에 모바일 cctv를 설치한 후, 수집된 데이터를 활용하여 음이항 회귀분석을 통해 보행사고 노출을 추정한다. 분석 결과 보 행사고 노출 변수들도 통계적으로 유의한 결과를 보인다. 분석 결과를 통해 보행사고 노출 추 정 모형을 개발하였고, 이를 통해 잠재적으로 보행사고 발생할 수 있는 구간을 도출하는 것에 활용될 수 있음을 보여준다. Pedestrian traffic needs to be accurately quantified to predict effectively pedestrian traffic accidents, however, pedestrian traffic is more difficult to measure than vehicle traffic. In this study, we suggest the time-and cost-effective application of mobile closed-circuit television (CCTV) using a smartphone as an alternative that can collect and analyze real-time data with little. In the present investigation, the pedestrian-vehicle conflict that can develop into an accident was defined as the pedestrian accident exposure. After installing mobile CCTV in 40 sections of Dongseong-ro, Daegu, the pedestrian accident exposure was estimated through negative binomial regression analysis using the collected data. The results of the analysis showed statistically significant changes in the pedestrian accident exposure variables. Based on the present results, a pedestrian accident exposure estimation model was developed which can be used in sections where pedestrian accidents may occur.

보행법 정착을 위한 우선과제

장일준 대한교통학회 2012 교통 기술과 정책 Vol.9 No.5

인간의 가장 기본적인 교통행위는 보행을 통해 이루어진다. 20세기 이전에는 안전하고 쾌적하게 걸을 수 있는 권리, 즉 보행권이 중요하게 여겨지 거나 문제가 되지 않았다. 그러나 교통수단의 발 달, 특히 자동차의 급격한 증가로 인해 교통정책 및 관련법이 소통위주의 자동차 중심으로 시행되 면서 보행이 위협받게 되었다. 지난해 보행 중 교 통사고 사망자는 전체 교통사고 사망자의 39% (2029명)에 이를 정도로 모든 길은 보행자가 아 닌 차를 위한 길이 되었다. 보행권이 위협받는 근 본적인 원인은 운전자와 보행자의 인식 차이라고 볼 수 있다. 시민 개인이 보행자인 경우 빠른 속도 의 차량에 위협받고 불법주차에 불편함을 느끼지 만, 차량의 운전석에 앉는 순간 보행자를 장애물로 여기게 된다. 안전을 보장받지 못하는 보행환경으 로 인해 보행자들은 차마와 같은 교통수단을 추구 하게 되고 교통량을 증가시키는 결과를 낳았다.

교통법규 위반 범칙금의 효율적 수준 설정 모형 개발 (신호와 제한속도 위반 중심)

장일준 대한교통학회 2009 대한교통학회지 Vol.27 No.3

Factors causing traffic accidents are various and traffic law violations can be among them. The efforts to increase traffic law obedience rates of drivers are common in many other countries to reduce traffic accidents, and one of generally applied methods is to increase the amounts of violation fines. Expensive levels of traffic law violation fines could have drivers choose “obey the law” in their decision-making stages since they are economically better-off by following the law. In this sense, this study has developed an economic model to verify whether the current levels of the traffic violation fines of Korea are effective for drivers to choose “obey-the-law” decisions. Speed violations and traffic signal violations have been selected for the case study to verify the relationships between “expected probabilities of being-caught” and “levels of violations fines”. 교통사고 발생은 도로 여건이나 운전자 의식 등의 문제로 발생할 수 있으나 운전자 상호간 또는 운전자와 보행자 사이의 지켜야할 사항을 규정하는 교통법규를 위반할 경우 차량 또는 보행자의 교통사고 노출 가능성이 높아져 교통사고로 이어지는 경우도 상당부분 발생한다. 따라서 교통안전 선진국에서는 이러한 메커니즘의 교통법규 준수율을 높이기 위해서 교통법규를 위반하는 운전자들이 경제적으로 부담을 느껴 “교통법규 준수”라는 행동을 선택할 수 있을 정도의 수준으로 교통법규 위반 범칙금을 책정하고 있으며, 경제가 발전 할수록 범칙금 수준도 향상 시키고 있는 실정이다. 반면, 우리나라는 국민 정서 문제를 앞세워 지난 20년간 교통법규 위반 범칙금 수준을 크게 향상시키지 않았다. 따라서 본 연구는 운전자의 교통법규 준수율을 높일 수 있는 방안에 대하여 경제논리를 적용하여 효율적 교통법규 위반 범칙금 수준을 책정하는 방안을 도출하였다. 속도위반 및 신호위반 등 교통사고와 연관성이 높은 교통법규 사항에 대하여 운전자의 “법규 위반” 또는 “법규 준수”의 행동 선택에 있어서의 기대효용을 수치화 하여 현재 운전자가 기대하는 “교통법규 위반 시 단속기대 확률”을 유지할 경우 적정 범칙금 수준과 현재의 범칙금 수준을 유지할 경우 “효율적 단속기대 확률” 등 두 가지의 교통정책 방안을 제시하였다.

교통안전, 정부가 나서라

장일준,Jang, Il-Jun 대한교통학회 2005 교통 기술과 정책 Vol.2 No.1

실도로 기반 E-scooter 경사로 주행 안전성 연구

장일준,이재덕,안세영,노찬우 한국ITS학회 2023 한국ITS학회논문지 Vol.22 No.6

With the increasing use of E-scooters, there is an urgent need for research into their driving risks because of the rising number of related accidents. Existing theoretical analysis methods are primarily vehicle-centered and do not adequately reflect the lightweight and compact characteristics of E-scooters. This study was conducted on real roads to analyze the risk and stable speeds of drivers on longitudinal slopes, considering the unique attributes of E-scooters. The risk speed on slopes was, on average, 21 km/h, with the initial risk speed decreasing as the slope became steeper. The stable speed was determined to be an average of 17 km/h, except on slopes of 1-2%, which presented a relatively low risk. These results are expected to contribute to the academic foundation for policies aimed at reducing the top speed of personal mobility, as is currently being promoted in Korea.

Modelling for Identifying Accident-Prone Spots: Bayesian Approach with a Poisson Mixture Model

장일준,김성욱 대한토목학회 2012 KSCE Journal of Civil Engineering Vol.16 No.3

In traditional identification of hot spots, often known as the sites with black spots or accident-prone locations, methodologies are developed based on the total number of accidents. These criteria provide no consideration of whether the accidents were caused or could be averted by road improvements. These traditional methods result in misidentification of locations that are not truly hazardous from a road safety authority perspective and consequently may lead to a misapplication of safety improvement funding. We consider a mixture of the zero-inflated Poisson and the Poisson regression models to analyze zero-inflated data sets drawn from traffic accident studies. Based on the membership probabilities, observations are well separated into two clusters. One is the ZIP cluster; the other is the standard Poisson cluster. A simulation study and real data analysis are performed to demonstrate model fitting performances of the proposed model. The Bayes factor and the Bayesian information criterion are used to compare the proposed model with several competing models. Ultimately, this model could detect accident-prone spots.

A Network-Based Model for Estimating the Market Share of a High-Speed Rail System in the Korean NW-SE Corridor

장일준(Chang, Il-Joon),Gang-Len Chang 대한교통학회 2003 대한교통학회 학술대회지 Vol.43 No.-

This research presents a novel application of static traffic assignment methods, but with a variable time value, for estimating the market share of a high-speed rail (HSR) in the NW-SE corridor of Korea which is currently served by the airline (AR), conventional rail (CR), and highway (HWY) modes. The proposed model employs the time-space network structure to capture the interrelations among all competing transportation modes, and to reflect their supply- and demand-sides constraints as well as interactions through properly formulated link-node structures. The embedded cost function for each network link offers the flexibility for incorporating all associated factors, such as travel time and fare, in the model computation, and enables the use of a distribution rather than a constant to represent the time-value variation among all transportation mode users. To realistically capture the tripmakers' value-of-time (VOT) along the target area, a novel method for VOT calibration has been developed with aggregate demand information and key system performance data from the target area. Under the assumption that intercity tripmakers often have nearly "perfect" travel information, one can solve the market share of each mode after operations of HSR for each O-D pair under the time-dependent demand with state-of-the-art traffic assignment. Aside from estimating new market share, this paper also investigated the impacts of HSR on other existing transportation modes.